Is this complete? Sad ending? For my sanity I need to know

Idk if it was complete but yeah it's sad ending but somewhat perfect for this story
It's one of those stories that hang with for a really long time, I watched the anime like when I was 17 and here I'm about to get married and it still gives me that warm ache in my chest

I thought the book ended differently than the anime, or is it only the novel that does?